The main shaft bearings of a wind turbine are critical components, which are expensive to replace if early failure occurs. Consequently, condition monitoring is often applied, whereby operating parameters of the bearing, such as temperature and vibration, are measured in order to send a maintenance alert if the measured values exceed predefined thresholds.
An example of a bearing assembly comprising a sensor unit embedded in a bearing ring of the assembly is disclosed in US 2016/0047715. A recess is machined into the bearing ring, which recess is sufficiently large to accommodate a housing of the sensor unit which, in addition to multiple sensors, includes electronics for processing and transmitting signals received from the sensors.
In some applications, however, it may not be possible or advisable to machine a recess of the requisite depth into the bearing ring. Consequently, there is room for improvement in terms of providing a sensor unit that is suitable for different types of bearings and bearing arrangements which support the main shaft of a wind turbine.